File folders, hanging file folders and other paper storage systems are of great utility in an office setting. The most common storage system, the common manila folder, for example are widespread and relatively inexpensive, and have convenient tabs suitable for writing.
In order to know what is in the file folder, it is useful to have protruding tabs such as shown in U.S. Pat. No. 8,746,539. It is commonly known to manufacture folders with tabs located at different locations across the top edge of the folder. That makes it possible for the user to see adjacent/back to back folder because the adjacent tabs are laterally offset. The problem with this solution is a) it requires the use and manufacture of multiple folders with tabs appropriately offset and b) if the user rearranges the folders, the tab offset may no longer be correct (it may be occluded by an adjacent folder) and thus require the user to change out the folder.
Solving this problem also involves creating a tab system which is robust enough to a) be reusable without damage and b) remain flat enough that the tab is easily readable at the desire angle.